Beverages based on the tea plant (Camellia sinensis) have been popular throughout the world for many hundreds of years. Traditionally such beverages are produced by infusing leaf tea in hot water.
Although many consumers still enjoy beverages made from leaf tea, it is becoming increasingly popular to enjoy tea beverages prepared in more convenient ways. For example, tea beverages can be prepared from instant powders which are free from insoluble leaf tea and so dissolve rapidly and completely on contact with hot water. These powder products are usually manufactured by a process comprising extracting leaf tea with water and drying the resulting extract. Also popular are packaged ready-to-drink beverages which contain dissolved tea solids. Such ready-to-drink teas are usually manufactured from instant powders such as those described above or directly from extraction of tea leaf.
Consumers are also increasingly interested in foods and beverages which have undergone minimal processing and have a natural image and/or contain high levels of bioactive compounds. In view of this, efforts have been made to manufacture tea powders or ready-to-drink beverages from juice expressed from tea leaves as an alternative to tea extracts.
CN 1 718 030 A (LANCANGJIANG BEER ENTPR GROUP) discloses a green tea beverage prepared from fresh organic green tea leaves through breaking, squeezing to obtain tea juice, filtering, fine filtering by membrane, mixing it with water in ratio of 1:(15-25), membrane filtering for removing bacteria, and aseptic canning.
JP 11/056,243 A (NARA PREFECTURE) discloses a method for producing a powdery tea product containing increased amount of effective component and capable of keeping flavour, etc., over a long period by subjecting a pressed juice obtained by the successive steaming, grinding and pressing of raw tea leaves to ultrafiltration and reverse osmosis concentration treatment, adding a cyclodextrin to the concentrated liquid and drying the mixture.
Unfortunately, tea products made from tea juice have not yet enjoyed commercial success. This may be due, in part, to high wastage due to loss of tea material in the pressed leaf. As disclosed in JP 11/056,243 A, the tea leaves from these known processes still contain some effective components but are unable to be used as they are. Thus, it is suggested in JP 11/056,243 A to process the squeezed leaves into a fine powder and recombine with the powdered tea juice. Unfortunately, however, products which contain powdered insoluble tea leaf are only of limited popularity with consumers.
Therefore, we have identified that there is a need for a process for preparing tea products derived from tea juice, wherein the pressed tea leaves are not wasted but are used to manufacture tea products which retain the high value of traditional leaf tea (especially large leaf tea) or tea extracts. We have found that this need can be met by carefully controlling the way in which the juice is expressed such that the leaves are suitable for manufacture into tea products with a quality at least comparable to that of conventional tea products.